Role of binder phase on properties and holding ability of WC based diamond hardbanding matrix

Diamond reinforced WC based cemented carbide shows potential for hardbanding applications, with its performance hinging on the matrix's toughness, strength, and diamond holding ability. However, a comprehensive theoretical understanding of enhancing mechanical properties and controlling microstructure during pressureless infiltration remains limited. In this study, WC based cemented carbide was fabricated via pressureless infiltration, and the effects of Ni and B content variations on the bending strength and microstructural characteristics of the composites were systematically investigated. The results demonstrated that WC based cemented carbide with Cu-Zn-Mn infiltration exhibited lower bending strength compared to Cu-Mn-Ni. However, with the addition of 4 wt%Ni, its bending strength (833.4 MPa) increased by 10.3 %, reaching a level comparable to that of Cu-Mn-Ni (861.3 MPa). B was added to two distinct diamond composites formulations—60 wt%WC/40 wt%Cu-Mn-Ni and 56 wt%WC/40 wt%Cu-Zn-Mn/4 wt%Ni—with varying proportions. The diamond composites with Cu-Zn-Mn infiltration reached maximum bending strength at 0.5 wt%B content, achieving 714.2 MPa. At the same time, the diamond holding force coefficient reached 85.7 %, surpassing that of Cu-Mn-Ni composites (82.9 %). The study further identified that controlled diamond surface etching and interfacial boron carbide formation were the primary contributors to enhanced diamond holding ability.